Abstract
Selective attention is typically studied with tasks that ask participants to identify relevant information (the target) for further processing while ignoring distractors. In cases where the target and distractors contain conflicting information, reaction times (RTs) are reliably slower compared to when there is no conflicting information, suggesting that attentional selectivity requires additional time to be deployed. How selective attention unfolds over time, however, is currently debated. There are two main accounts that explain temporal dynamics of attentional selectivity: one proposes that attentional selectivity increases continuously over time (Heitz & Engle, 2007), and the other proposes that attention transitions from a low- to a high-state of selectivity at a discrete point in time (Hübner, Steinhauser & Lehle, 2010). While both accounts successfully explain RT data, there is no direct empirical evidence that distinguishes them. In the present study, we utilized mouse-tracking to record real-time response trajectories in a flanker task. On each trial, participants were presented with five colored stimuli where the identity of the central target corresponded to one of two response locations. The task was to move the mouse cursor and click on the correct response location. The target was flanked by distractors that were either the color of the opposite response mapping (incongruent), a color that was unassociated with a response mapping (neutral), or the same color (congruent). Replicating previous studies, we found slower RTs for incongruent trials compared to neutral trials. Furthermore, response trajectories for incongruent trials curved more toward the incorrect response location compared to neutral trials, suggesting greater distractor interference on selective attention. Importantly, our results showed that this attraction to the incorrect location evolved gradually over time and smoothly transitioned toward the correct response location, as opposed to abruptly shifting at discrete points in time, demonstrating a continuous implementation of selective attention.